Multi-Monitor-Handling is improved in W11. As the same really sucks in W10, if you have such a setup (like using both an external and your notebook screen at the same time in your home office) you might benefit immediately by upgrading. Unfortunately my employer-managed notebook in my home office setup, which would benefit from this the most, won't get W11 for a long time to come. Our IT support is rather conservative on this.

Once the Alder Lake CPUs of Intel are released, W11 will have the right scheduler for those, W10 maybe not. Those CPUs should be able to make better use of batteries in notebooks. I will upgrade my Surface Pro, once they appear with those CPUs on board.

I thought that WSL2 would be another reason but all improvements to that (like WSLg) come to W10 as well.